The present invention relates to a water delivery system.
A typical water delivery system comprises one or several sinks, a cold water line to the sinks and a hot water line to the sinks. The hot water is heated, e.g., in a boiler. In such a system the problem arises that hot water in the hot water line cools down. When a hot water faucet is opened, the running water is initially cold water and only after some time does hot water flow.
As a remedy for this problem, it is well-known to re-circulate, while faucets are closed, hot water from the hot water line to the cold water line. Too strong a cooling-down of the hot water in the hot water line leading to the hot water faucet is thus prevented.
The invention also relates to a valve for a sink.
WO 98/43143 A1 discloses a regulator, in particular a circulation regulator for supplying warm water to a user, a combination set or other such consumer. A connection between a warm water pipe and a cold water pipe is established or interrupted in the regulator in accordance with the temperature.
U.S. Pat. No. 6,536,464 B1 discloses a thermostatically controlled bypass valve.
U.S. Pat. No. 6,895,985 B2 discloses a water delivery device comprising a hot water inlet coupled to a hot water pipe, a cold water inlet coupled to a cold water pipe, a first outlet operative to receive hot and cold water flows from the hot and cold water inlets and to facilitate water delivery to a user, and a circulation mechanism operative to allow circulation of water from the hot water pipe to the cold water pipe prior to delivery of water at a desired temperature to the user through that first outlet, wherein the circulation mechanism further includes a controller responsive to input from at least one temperature sensor and operative to control the circulation.
U.S. Pat. No. 7,073,528 B2 discloses a water pump and bypass valve sub-system for use in a water delivery system comprising a thermostatically controlled bypass valve.
U.S. Pat. No. 5,983,922 discloses a hot and cold water distribution system.
U.S. Pat. No. 3,120,854 discloses a fluid pressure equalizing assembly.
JP 2006-145182 discloses a header for a hot water supply system.
U.S. Pat. No. 4,945,942 discloses a plumbing system comprising a hot water recovery means for drawing hot water from a conduit means into a hot water source subsequent to withdrawal of hot water from the plumbing fixture, hot water withdrawn from the conduit being replaced by cold water passing through a one-way valve means.
U.S. Pat. No. 5,277,219 discloses a hot water recovery system.
U.S. Pat. No. 5,042,524 discloses a demand recovery hot water system comprising a transfer tank with a moveable piston.